# Why a 24 hour reference **URL:** \ **Category:** Factual Questions\ **Created:** [January 18, 2012, 10:07am UTC](https://boards.straightdope.com/t/why-a-24-hour-reference/609890 "2012-01-18T10:07:18Z")\ **Posts on this page:** 15\ **Page:** 2
**Author:** ![standingwave](https://avatars.discourse-cdn.com/v4/letter/s/9de0a6/32.png) [@standingwave](https://boards.straightdope.com/u/standingwave)\ **Post date:** [January 18, 2012, 7:39pm UTC](https://boards.straightdope.com/t/why-a-24-hour-reference/609890/21 "2012-01-18T19:39:24Z")
Obligatory link to the [Dozenal Society of GB.](http://www.dozenalsociety.org.uk/) The Dozenal Society of America and the Dozenal Society of Great Britain promote widespread adoption of the base-twelve system. They use the word dozenal instead of “duodecimal” because the latter comes from Latin roots that express twelve in base-ten terminology. ---
**Author:** ![treis](https://avatars.discourse-cdn.com/v4/letter/t/bc79bd/32.png) [@treis](https://boards.straightdope.com/u/treis)\ **Post date:** [January 18, 2012, 8:28pm UTC](https://boards.straightdope.com/t/why-a-24-hour-reference/609890/22 "2012-01-18T20:28:24Z")
> [@Zep\_Tepi](#): > > I still cannot understand why 12 or 24 as we use the base 10 in counting and have done for the last 2000 years. Base 10 was obviously taken as the base as we have 5 digits on each hand. Have you ever watched a child count on their fingers. Children learn to count from adults. It would be easy to count to 12 using hands. Simply go 1-5 the normal way, close that hand for 6, 7-11 the normal way, and then close the other hand for 12. ---
**Author:** ![Lemur866](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lemur866/32/434_2.png) [@Lemur866](https://boards.straightdope.com/u/Lemur866)\ **Post date:** [January 18, 2012, 8:32pm UTC](https://boards.straightdope.com/t/why-a-24-hour-reference/609890/23 "2012-01-18T20:32:21Z")
We haven’t used base 10 year 2000 years. Roman numerals aren’t strictly base 10, they aren’t exactly base anything. They have digits for ones, fives, tens, fifties, hundreds, five hundreds and thousands. “Bases” only make sense in the context of Arabic (actually Indian) numerals, and when Arabic numerals were created they were base 10, not base 12. Counting by dozens was a very widespread practice, and still is in some cases. Arabic numerals only started to be used in the 1300s in Europe. So that’s 700 years, not 2000. ---
**Author:** ![naita](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/naita/32/5862_2.png) [@naita](https://boards.straightdope.com/u/naita)\ **Post date:** [January 18, 2012, 8:43pm UTC](https://boards.straightdope.com/t/why-a-24-hour-reference/609890/24 "2012-01-18T20:43:08Z")
> [@Lemur866](#): > > We haven’t used base 10 year 2000 years. Roman numerals aren’t strictly base 10, they aren’t exactly base anything. They have digits for ones, fives, tens, fifties, hundreds, five hundreds and thousands. > > “Bases” only make sense in the context of Arabic (actually Indian) numerals, and when Arabic numerals were created they were base 10, not base 12. Counting by dozens was a very widespread practice, and still is in some cases. Arabic numerals only started to be used in the 1300s in Europe. So that’s 700 years, not 2000. Indeed. Something as, to us, conceptually base ten as a hundred was 120 in old Norse, and was used as such in some trades in Norway until the 19th century. For the latter few hundred years it was called big hundred to distinguish it from the new purely decimal hundred. ---
**Author:** ![Saint\_Cad](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/saint_cad/32/18907_2.png) [@Saint\_Cad](https://boards.straightdope.com/u/Saint_Cad)\ **Post date:** [January 18, 2012, 8:44pm UTC](https://boards.straightdope.com/t/why-a-24-hour-reference/609890/25 "2012-01-18T20:44:18Z")
It was once explained to me that as the circumference of the Earth is 24,000 miles, the Babylonians decided on 24 hours in a day so that the equator moves at an even 1000 mph. I didn’t even know where to start to argue that. ---
**Author:** ![standingwave](https://avatars.discourse-cdn.com/v4/letter/s/9de0a6/32.png) [@standingwave](https://boards.straightdope.com/u/standingwave)\ **Post date:** [January 18, 2012, 9:28pm UTC](https://boards.straightdope.com/t/why-a-24-hour-reference/609890/26 "2012-01-18T21:28:54Z")
> [@treis](#): > > Children learn to count from adults. It would be easy to count to 12 using hands. Simply go 1-5 the normal way, close that hand for 6, 7-11 the normal way, and then close the other hand for 12. It’s even possible to count to 12 using a single hand, with your thumb acting as a pointer touching each finger bone, i.e. phalange (proximal, medial, and distal) in turn. If a positional notation is employed then one could use one’s hands to count to 144. ---
**Author:** ![Smeghead](https://avatars.discourse-cdn.com/v4/letter/s/f1d935/32.png) [@Smeghead](https://boards.straightdope.com/u/Smeghead)\ **Post date:** [January 18, 2012, 10:07pm UTC](https://boards.straightdope.com/t/why-a-24-hour-reference/609890/27 "2012-01-18T22:07:06Z")
It was the Babylonians that started the base 12 system, for reasons best understood by them. There are certainly benefits, as has been stated. The fact that a few things - time and angles come to mind - are still calculated in base 12 while everything else has moved to base 10 is just an accident of history. ---
**Author:** ![Do\_Not\_Taunt](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/do_not_taunt/32/2968_2.png) [@Do\_Not\_Taunt](https://boards.straightdope.com/u/Do_Not_Taunt)\ **Post date:** [January 18, 2012, 10:19pm UTC](https://boards.straightdope.com/t/why-a-24-hour-reference/609890/28 "2012-01-18T22:19:49Z")
A lot of East African countries use the Swahili time-keeping system, which works like the standard western system, except the day begins at 6am, which is roughly daybreak. Sometimes, it can be confusing to understand what time system someone’s referring to, although the standard is usually to use western time when speaking in English. I remember thinking at the time that it made sense that people who evolved their time system in equitorial regions when daybreak was fairly consistent would start the day then, whereas people who evolved their time system in the mid-latitudes where daybreak can move by hours throughout the year would pick a time in the middle of the night to begin their day. I only have two data points, so I’m not sure if that holds true across other peoples. ---
**Author:** ![Zep\_Tepi](https://avatars.discourse-cdn.com/v4/letter/z/59ef9b/32.png) [@Zep\_Tepi](https://boards.straightdope.com/u/Zep_Tepi)\ **Post date:** [January 19, 2012, 8:30am UTC](https://boards.straightdope.com/t/why-a-24-hour-reference/609890/29 "2012-01-19T08:30:51Z")
I can’t remember where I saw it, but the base 10 was used by the Jews 2000 years ago. The 1 had one angle, the 2 had two angles the 3 three angles, the 4, which was drawn as a cross had 4 angles and upwards to 9 that was the figure 8 drawn as two boxes, (8 angles) but had a tail giving the extra angle. The circle had no angles at all. This is possibly where some people put a cross on the leg of the 7 to make up the 7 angles. The place where I believe I found this information said it was used by the Jews so that the occupying Romans did not know what it meant. I wonder if anyone can confirm this snippet. ---
**Author:** ![naita](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/naita/32/5862_2.png) [@naita](https://boards.straightdope.com/u/naita)\ **Post date:** [January 19, 2012, 1:12pm UTC](https://boards.straightdope.com/t/why-a-24-hour-reference/609890/30 "2012-01-19T13:12:20Z")
> [@Zep\_Tepi](#): > > I can’t remember where I saw it, but the base 10 was used by the Jews 2000 years ago. The 1 had one angle, the 2 had two angles the 3 three angles, the 4, which was drawn as a cross had 4 angles and upwards to 9 that was the figure 8 drawn as two boxes, (8 angles) but had a tail giving the extra angle. The circle had no angles at all. This is possibly where some people put a cross on the leg of the 7 to make up the 7 angles. > > The place where I believe I found this information said it was used by the Jews so that the occupying Romans did not know what it meant. > > I wonder if anyone can confirm this snippet. From the wikipedia article on the western arabic numerals, of which this tale is often told: Folk etymologies “Some folk etymologies argue that the original forms of these symbols indicated their value through the number of angles they contained, however there is no proof of any such origin.” ---
**Author:** ![jjimm](https://avatars.discourse-cdn.com/v4/letter/j/ba8739/32.png) [@jjimm](https://boards.straightdope.com/u/jjimm)\ **Post date:** [January 19, 2012, 1:16pm UTC](https://boards.straightdope.com/t/why-a-24-hour-reference/609890/31 "2012-01-19T13:16:27Z")
> [@Chessic\_Sense](#): > > The 24-hour clock, not being hard to understand, is in wide use among Americans that need to use it, as well, such as nurses, pilots, hotel desk attendants, night watchmen, firefighters, and so on. Like many simple things, the only ones that don’t know it have no need for it. Elsewhere, it reduces ambiguity for things that the general public come into contact with like airline tickets, bus/train timetables, etc. From experience designing web forms with the US market in mind is a bit of a pain because we have to add in the am/pm thing rather than use 24-hour which the rest of the world understands. ---
**Author:** ![Floater](https://avatars.discourse-cdn.com/v4/letter/f/dc4da7/32.png) [@Floater](https://boards.straightdope.com/u/Floater)\ **Post date:** [January 19, 2012, 3:02pm UTC](https://boards.straightdope.com/t/why-a-24-hour-reference/609890/32 "2012-01-19T15:02:47Z")
British time tables, TV program listings and such things used to be a pain in the behind when they gave just the hour on a 12 hour format without adding pm or am. I remember, when UK switched from from 12 to 24, an Open University program on TV where people were taught how to rethink their clocks and the relationship between 3 pm and 15. It was quite funny for me who had grown up with system. ---
**Author:** ![SGT42](https://avatars.discourse-cdn.com/v4/letter/s/b9e5f3/32.png) [@SGT42](https://boards.straightdope.com/u/SGT42)\ **Post date:** [January 19, 2012, 7:06pm UTC](https://boards.straightdope.com/t/why-a-24-hour-reference/609890/33 "2012-01-19T19:06:34Z")
> [@Smeghead](#): > > It was the Babylonians that started the base 12 system, for reasons best understood by them. There are certainly benefits, as has been stated. The fact that a few things - time and angles come to mind - are still calculated in base 12 while everything else has moved to base 10 is just an accident of history. The babylonians used a base 60 system. That is the origin of 360 degrees to the circumference, 60 minutes to the degree and 60 seconds to the minute. Why 360 degrees? Because the astronomers (or astrologers) remarked that each day the sun would rise at a slightly different place relative to the background stars. After 365 1/4 days it would rise in the initial position. Replacing 365 1/4 by 360 offered a more manageable number, so we can say that the Sun travels one degree each day, relative to the Zodiac. ---
**Author:** ![robert\_columbia](https://avatars.discourse-cdn.com/v4/letter/r/e79b87/32.png) [@robert\_columbia](https://boards.straightdope.com/u/robert_columbia)\ **Post date:** [January 19, 2012, 11:47pm UTC](https://boards.straightdope.com/t/why-a-24-hour-reference/609890/34 "2012-01-19T23:47:52Z")
> [@standingwave](#): > > It’s even possible to count to 12 using a single hand, with your thumb acting as a pointer touching each finger bone, i.e. phalange (proximal, medial, and distal) in turn. If a positional notation is employed then one could use one’s hands to count to 144. I can count to 31 (0-31) on one hand, and up to 1023 with two hands. Guess how. ---
**Author:** ![standingwave](https://avatars.discourse-cdn.com/v4/letter/s/9de0a6/32.png) [@standingwave](https://boards.straightdope.com/u/standingwave)\ **Post date:** [January 20, 2012, 4:18am UTC](https://boards.straightdope.com/t/why-a-24-hour-reference/609890/35 "2012-01-20T04:18:46Z")
> [@robert\_columbia](#): > > I can count to 31 (0-31) on one hand, and up to 1023 with two hands. Guess how. I can count to a million if I’m allowed to use my toes but I wouldn’t seriously propose binary as a number system. 😃 [Previous page](https://boards.straightdope.com/t/why-a-24-hour-reference/609890.md?page=1)